This invention relates to apparatus for transferring the setting of process control elements from a process simulating apparatus to a process machine. In particular, the invention is useful in connection with a system for previewing the operation of a color scanner and for transferring the control element settings from the previewer system to the scanner.
FIG. 1 illustrates the process typically used for the manufacture of color prints. This process employs a color scanner 12 comprising units 11, 13, 14 and 16. The color original 10, which may be a photographic print or color transparency is mounted to a rotating drum 11. A light detector 13 detects the component color content of the image 10 as various segments of the image are sequentially scanned, by rotating drum 11 and by moving detector 13 across image 10 in a direction corresponding to the axis of drum 11. The output of detector 13 is in the form of video signal representative of the amplitude of the various color components in sequentially scanned portions of image 10 which are provided to color correction computer 14. These signals are usually representative of the yellow, magenta, and cyan color content of image 10 and are represented in FIG. 1 by the letters Y, M, and C. Color correction computer 14 is equipped with circuits for enhancing, correcting and cross-correlating the component color signals and is connected to exposure apparatus 16 which provides a set of color separations. Usually four separations are made, each separation is a black and white transparent image representative of a single color component in the original image. Where four separations are provided they are usually representative of the yellow, magenta, cyan, and black components of the image. The color separations are used in the etching of printing plates or cylinders 20. One cylinder or plate is made corresponding to each of the four separations and separations and the plates are used with corresponding colored inks to sequentially print the component color images on paper, to result in a composite color image having all of the component colors.
Color correction computer 14 is provided with many control elements for changing the characteristics of the color separations manufactured by the scanner 12. FIG. 6 illustrates the control panel of a typical prior art color correction computer. It should be noted that the control panel contains 89 different control elements including switches and potentiometers. The control elements are arranged in an order corresponding to the four color separations which the scanner manufactures and the various controls, where applicable, are indicated Y, M, C, and B as a prefix to the control number. Control numbers unrelated to a particular separation are labeled S for switches, and R for potentiometers. The single meter has the prefix D.
With the large number of controls available on a typical color scanner, the quality of the separations produced is largely dependent upon the skill of the scanner operator. Based on the operator's evaluation of the color original, it is necessary for him to make adjustments to the control panel in a manner which he feels will produce separations which will make an acceptable color print in the actual printing process. After a first set of separations has been made, it is necessary to manufacture printing cylinders or plates and actually apply ink to paper to determine whether the operator's judgment is correct. If the resulting print does not satisfy the operator or editor, it is necessary for the operator to adjust the control panel of the color scanner and repeat the process making new separations and printing plates. Alternatively, the color separations or printing plates might be modified by etching or other processes.
In order to facilitate the production of color prints, there have been developed color printing previewing apparatus which simulate the operation of the color scanner, including the color correcting computer. One such previewing apparatus 23 is illustrated in FIG. 2 wherein the color original 10 is scanned by a video signal generating apparatus 24 which may be a color TV camera or similar device. Video signal generator 24 produces video signals representative of the elementary colors in image 10 and provides them to a color correction computer 26 which is similar or identical to the color correction computer 14 used in the scanner of FIG. 1. The output of the color correction computer 26 consists of video signals representative of the color separations 18 used in the actual printing process. These are supplied to a printing simulator computer 28 which modifies the video signals in accordance with the characteristics of the particular printing process being used. The output signal from printing simulator 28 are provided to a color display unit 30 which provides a color display image representative of the resulting color print which would be produced using a printing process with the color correction computer control elements set in accordance with the setting of the control elements of computer 26.
An operator using the previewing apparatus 23 can adjust the color correction control elements while viewing display 30 and arrive at a set of control settings which when applied to the actual color correction computer 14 of the color scanner 12 will result in an acceptable set of color separations which will produce the desired qualities in the color print 22. As noted above, both the color correction computer 14 and its simulator 26 may have on the order of ninety control elements. It is both tedious and time consuming for an operator to manually adjust each of the control elements of the color correction computer 14 in the color scanner 12 in accordance with the readings of the corresponding control elements on the previewer 23.
It is therefore an object of the invention to provide a practical, accurate, and inexpensive apparatus for transferring the control element settings from a process simulating apparatus to a process machine.
It is a further object of the invention to provide such an apparatus wherein the process simulating apparatus may be used separately from the process machine and the control settings transferred at the convenience of the operator of the process machine.